78 terms, in plain English

What all the words mean

Kidney care has a language of its own, and everybody in the room speaks it except you. People come out of clinic holding a word they did not understand and did not feel able to ask about, because the conversation had already moved on.

This page is for that. Search for the word, or browse the letters. There is no jargon in the definitions, and there is nothing here you are expected to already know.

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Showing all 78 terms.

AccessAccess: The way blood gets in and out of your body for haemodialysis. There are three kinds: a fistula, a graft, or a catheter. Your access is your lifeline, which is why so much care goes into protecting it.
ACRTests and numbers: A urine test that measures how much protein (albumin) is leaking into your urine. It is one of the key markers of kidney damage, and it is used alongside eGFR to work out how serious kidney disease is.
AdequacyTests and numbers: Whether a dialysis treatment is doing enough. It is usually measured with Kt/V or URR, but the number never tells the whole story: how you feel, your fluid balance, your blood pressure and your nutrition matter just as much.
AlbuminuriaTests and numbers: Protein (albumin) in the urine. It is a sign that the kidney filters are leaking. Two people can have the same eGFR and be at very different risk depending on how much albumin they are losing.
AnaemiaComplications: Too few red blood cells, so less oxygen is carried around the body. It causes tiredness and breathlessness, and it is very common in kidney failure, because failing kidneys make too little of the hormone that tells the bone marrow to make red cells.
AnuriaTests and numbers: Passing no urine at all. Many people on dialysis keep passing some urine for months or years, and that remaining urine is valuable, because it means a more generous fluid allowance.
APDTreatments: Peritoneal dialysis done overnight by a machine, called a cycler, while you sleep. It typically runs three to five cycles during the night. You connect at bedtime and disconnect in the morning, so your days are mostly free.
AV fistulaAccess: A join made surgically between one of your own arteries and one of your own veins, usually in the arm. The vein thickens and enlarges over weeks to months so it can take the dialysis needles. It gives the best blood flow and lasts longest of the three access types.
AV graftAccess: A join between an artery and a vein made with a synthetic tube. It can be used sooner than a fistula, often within weeks, but it is more prone to clotting and infection.

BruitAccess: The whooshing sound heard through a stethoscope over a working fistula or graft. Staff listen for it, and for changes in its character, as one of the ways of checking that your access is healthy.
Buttonhole techniqueAccess: A way of needling a fistula in exactly the same two spots each time, so a soft tunnel forms. Some units teach it; others rotate needle sites instead. Both approaches exist to stop a single spot being punctured over and over until it bulges.

CalcimimeticMedicines: A medicine that lowers parathyroid hormone by making the parathyroid gland more sensitive to calcium. Cinacalcet is taken as a tablet, and etelcalcetide is given into the dialysis circuit.
CalciphylaxisComplications: A rare but very serious condition in which calcium deposits in small blood vessels of the skin, causing intensely painful purple patches that can break down into ulcers. Painful skin lesions in someone on dialysis should never be dismissed. Tell your unit.
CannulationAccess: Putting the two dialysis needles into a fistula or graft: one to take blood out, one to return it. The needles are larger than blood-test needles. Most units offer local anaesthetic cream or an injection, and most people find it gets much easier as the fistula toughens and the staff get to know their access.
CAPDTreatments: Peritoneal dialysis done by hand, with no machine, usually four or more times a day. Each exchange takes about 30 to 40 minutes, and the fluid dwells inside you for several hours in between.
CatheterAccess: A soft tube placed into a large vein, usually in the neck, that can be used for haemodialysis straight away. It needs no needles. It carries the highest infection risk of the three access types, which is why it is usually the last choice, but it is the right choice for someone who needs dialysis this week or who has run out of other options.
CKDTests and numbers: Kidney damage, or reduced kidney function, lasting more than three months. The word chronic simply means long-standing. It is graded by cause, by how well the kidneys filter (eGFR), and by how much protein is leaking (albuminuria).
CKD-MBDComplications: The whole cluster of calcium, phosphate, parathyroid hormone, bone and blood-vessel problems caused by kidney failure. It is why phosphate binders, vitamin D analogues and blood tests for calcium and PTH are such a large part of dialysis care.
Conservative careTreatments: Actively treating kidney failure and its symptoms without dialysis or a transplant. It is a legitimate treatment choice, not doing nothing and not giving up: it includes treating anaemia, fluid, itching, nausea, breathlessness and pain, reviewing medicines, dietetic help, planning ahead, and palliative support. It is everything except dialysis.
CrossmatchTransplant: A laboratory test in which your blood is tested against a potential donor kidney to check that your immune system will not immediately attack it. It is part of the transplant work-up.
CyclerTreatments: The machine that performs peritoneal dialysis exchanges overnight in automated peritoneal dialysis. It fills, dwells and drains for you while you sleep.
Cystatin CTests and numbers: A different blood marker that can be used to estimate kidney function. It is used to double-check a creatinine-based eGFR when a more accurate figure would change what happens next, for example in someone with very high or very low muscle mass.

DAFBTravel: Having your dialysis at a unit that is not your usual one, so that you can travel. It is not really a booking: it is a clinical handover between your unit and theirs, which is why the paperwork is heavy and the lead times are long.
DialysateTreatments: The fluid on the other side of the filter, which waste products and excess salts move into. Its exact recipe, including how much potassium, calcium, sodium and bicarbonate it contains, is part of your prescription and is chosen for you.
DialyserTreatments: The filter itself in haemodialysis: the cartridge your blood passes through. It is sometimes called the artificial kidney, although it does only part of what a kidney does.
DialysisTreatments: Treatment that does some of the work of failing kidneys: removing waste products and excess fluid, and helping keep salts such as potassium in a safe range. It replaces part, but not all, of your kidney function, which is why diet, fluid limits and medicines are still needed alongside it.
Disequilibrium syndromeComplications: A reaction that can happen if waste is cleared from the blood faster than it leaves the brain, causing headache, nausea, restlessness or confusion. It is why your first dialysis session is deliberately short and gentle. That is a safety measure, not a sign that anything has gone wrong.
Dry weightDiet and fluid: Your weight when you have no excess fluid on board. The machine removes the difference between what you weigh today and your dry weight. Being weighed before every session is not a judgement, it is the prescription.
DwellTreatments: In peritoneal dialysis, the time the fluid sits inside your abdomen doing its work before it is drained out. On CAPD a dwell typically lasts four to six hours or more, including a long one overnight.

eGFRTests and numbers: A number calculated from a blood test that estimates how well your kidneys are filtering. It is an estimate, not a measurement, and it is less reliable in some people. It is a warning light, not a starting gun: the decision to begin dialysis is driven by symptoms, not by the number alone.
ESAMedicines: An injected medicine that replaces the hormone (erythropoietin) that failing kidneys stop making, to treat anaemia. It cannot work without enough iron, which is why iron is usually sorted out first.
ESKDTests and numbers: Kidney failure that needs dialysis or a transplant. Many patients and clinicians now prefer the words kidney failure, because end-stage sounds bleak and is not really accurate: people live for many years at this stage.
ExchangeTreatments: One complete cycle of peritoneal dialysis: drain the old fluid out, run new fluid in, and let it dwell. On CAPD you do this by hand at least four times a day, each taking about 30 to 40 minutes.

FerritinTests and numbers: A blood test that reflects how much iron is stored in the body. It also rises with inflammation, so it can be misleadingly high, which is why it is read alongside TSAT rather than on its own.
Fluid overloadComplications: Too much fluid in the body. It causes swelling of the ankles, face or abdomen, breathlessness, high blood pressure, headaches and strain on the heart. New swelling or new breathlessness is a reason to contact your unit today, not to wait for the next session.

HaemodialysisTreatments: Dialysis using a machine and a filter outside the body. Blood is pumped out through the filter and returned to you. Only about a cupful is outside your body at any one moment. It is usually done three times a week for about four hours, either at a unit or at home.
HIF-PHIMedicines: A newer class of tablet for the anaemia of kidney disease, and an alternative to injected ESAs. Guideline bodies currently disagree about where it sits: KDIGO suggests ESAs first, while European Renal Best Practice argues both should be options.
HyperkalaemiaComplications: Too much potassium in the blood. It is dangerous because it can disturb the heart rhythm and, at high levels, stop the heart. Risk is highest after the long gap between sessions and after a missed session. Palpitations with dizziness, or a very slow or very irregular pulse, are an emergency.

IcodextrinMedicines: A type of peritoneal dialysis fluid that pulls water off slowly over a long dwell, which is why it is used for the long overnight or daytime dwell. Unlike the standard fluids it is not sugar-based.
ImmunosuppressantsTransplant: The medicines a transplant recipient must take every day, for as long as the kidney works, to stop the body rejecting it. Stopping them, even briefly, risks rejection. They also raise the risk of infection and of some cancers, particularly skin cancer, which is why sun protection matters so much afterwards.
Interdialytic weight gainDiet and fluid: The fluid weight you put on between dialysis sessions. Bigger gains mean the machine has to take fluid off harder and faster, which is what causes cramps, blood pressure crashes and the washed-out feeling afterwards. The most effective way to reduce it is usually to eat less salt, not to try harder not to drink.
Intradialytic hypotensionComplications: Blood pressure dropping during a haemodialysis session. It is the commonest side effect of haemodialysis. It can feel like light-headedness, nausea, yawning, sweating, cramp or tunnel vision, and sometimes there are no symptoms at all. Staff manage it by laying the chair flat, slowing or stopping fluid removal, and giving fluid if needed.
IronMedicines: The raw material for haemoglobin. Iron deficiency is very common on dialysis, because blood is lost in the circuit and in blood tests, absorption from the gut is poor, and inflammation blocks iron being released from stores. In haemodialysis it is usually given straight into the dialysis circuit.

KDIGOGuidelines and bodies: The main international guideline body for kidney disease. When this site says "guidelines suggest", KDIGO is often who it means.
KDOQIGuidelines and bodies: The guideline programme of the US National Kidney Foundation. It publishes the widely used guidelines on haemodialysis adequacy, vascular access and nutrition.
KFRETests and numbers: A calculator that estimates the risk of needing dialysis or a transplant within the next two or five years. Modern guidelines lean on it because two people at the same CKD stage can be at very different risk.
Kt/VTests and numbers: A number describing how much urea a dialysis session cleared, relative to your body size. It is the standard measure of dialysis adequacy. It is worth knowing what it does not measure: one small waste molecule, and nothing about your fluid, your phosphate or how you feel.

MaturationAccess: The process by which a new fistula enlarges and toughens over weeks to months until it can take dialysis needles. Fistulas fail to mature reasonably often. That is a known, common outcome, not a personal failure, and it is why a back-up plan is made from the start.

NephrologistGuidelines and bodies: A doctor who specialises in kidney disease. Being referred to one early matters: it is what makes a planned start, a fistula, a home therapy or a pre-emptive transplant possible, rather than an emergency start on a catheter.
Nocturnal dialysisTreatments: Longer, gentler haemodialysis performed overnight, at home or in some units, three to six times a week. Because fluid comes off slowly over many hours, it is usually kinder to the body and allows a more liberal diet and fluid allowance.

Peritoneal dialysisTreatments: Dialysis that uses the peritoneum, the lining inside your own abdomen, as the filter. Fluid runs in through a soft catheter, dwells, and is drained out. It is done at home, by you, every day. No needles, a gentler rhythm and usually a more liberal diet, at the cost of a permanent tube and the risk of peritonitis. Peritoneal dialysis is not documented as available in Seychelles, so do not assume it is.
PeritoneumTreatments: The thin lining of the inside of your abdomen. In peritoneal dialysis it is the filter. It can wear out over years, which is why peritoneal dialysis is often not a lifetime treatment and a move to haemodialysis may eventually be needed.
PeritonitisComplications: Infection of the peritoneum, and the main risk of peritoneal dialysis. Cloudy drained fluid, with or without tummy pain, is peritonitis until proven otherwise. Contact your unit the same day, do not wait, and bring the drained bag with you.
PhosphateDiet and fluid: A mineral that builds up in kidney failure. Over time, high phosphate pulls calcium out of the bones and helps deposit it in blood vessels, the heart and the eyes. It also drives itching. The most useful thing to know is that phosphate added to processed food is almost completely absorbed, while the phosphate naturally present in beans, nuts and grains is not, so cutting processed food does far more good than cutting lentils.
Phosphate binderMedicines: A tablet taken with food that traps phosphate in the gut so it is not absorbed into the blood. It has to be in your stomach at the same time as the food, which is why it is taken with every meal and snack. A binder taken away from food does almost nothing.
PotassiumDiet and fluid: A salt that has to stay within a narrow safe window: too high is dangerous for the heart, and too low is dangerous as well. There is no single potassium limit that applies to everyone. Guidelines now say intake should be individualised to keep your blood level normal, and, importantly, many people on peritoneal dialysis run low and are told to eat more potassium, not less.
Pre-emptive transplantTransplant: A kidney transplant performed before dialysis is ever needed. It gives the best outcomes, and it requires early referral, because the work-up takes months. The question "should I be referred for a transplant assessment?" is worth asking long before dialysis is on the table.
ProteinDiet and fluid: Something that catches people out. Before dialysis, protein is often restricted. Once dialysis starts, protein intake needs to go up, roughly doubling, because dialysis removes amino acids and peritoneal dialysis removes protein directly into the fluid. Carrying the pre-dialysis low-protein rules into dialysis is a known way to become malnourished.
Protein-energy wastingDiet and fluid: Losing muscle and body stores because you are not eating enough protein and calories for what dialysis and illness are taking out of you. It is common and it is dangerous. Malnutrition harms more people on dialysis than the occasional high-potassium meal does, which is why "eat less" is not automatically the safer advice.
PTHTests and numbers: A hormone that controls calcium. It rises in kidney failure and, if it stays high, it damages bones and blood vessels. It is one of the numbers your team watches over time rather than reacting to a single result.

RejectionTransplant: When the immune system attacks a transplanted kidney because it recognises it as foreign. It is what the daily anti-rejection medicines exist to prevent. Transplants do not last forever, and a graft failing after years is not a personal failure.
Residual kidney functionTests and numbers: The work your own kidneys are still doing after dialysis has started. It is genuinely precious: while you still have it, you can usually have a more liberal diet and a more generous fluid allowance. It usually declines with time, and it is typically preserved for longer on peritoneal dialysis.
RRTTreatments: The umbrella term for dialysis and transplant, meaning the treatments that replace the work of failed kidneys. Conservative care is the fourth path, and it sits alongside these rather than inside them.

SensitisationTransplant: Having antibodies in your blood, usually from a previous transplant, a pregnancy or a blood transfusion, that make finding a compatible donor kidney much harder. It is one reason transplant candidates are given blood transfusions sparingly.
SodiumDiet and fluid: The real lever behind fluid. Salt makes you thirsty, thirst makes you drink, drinking drives up your weight between sessions, and that forces the machine to pull fluid off harder, which is what causes crashes and cramps. The most useful fluid advice is usually not "drink less", it is "eat less salt, and you will want to drink less". Be careful with salt substitutes: most of them are potassium chloride.
Steal syndromeComplications: When a fistula or graft diverts so much blood that the hand beyond it goes short. It causes a cold, painful, numb, weak or pale hand on the access side. A strong thrill does not rule it out. Contact your unit the same day.
StenosisComplications: A narrowing, usually of the vein in a fistula or graft, which reduces flow and can lead to clotting. Signs can include a change in the thrill or the bruit, a swollen arm, or prolonged bleeding after needles come out.

ThrillAccess: The buzz or vibration you can feel over a working fistula or graft. Feel for it several times every day. If it becomes weak, changes, or disappears, the access may be clotting: contact your unit immediately, because it may still be saved if it is treated within hours.
TransplantTransplant: Receiving a kidney from a living or deceased donor. It is the best treatment for kidney failure for those who are suitable, but it is a treatment, not a cure: it trades dialysis for lifelong anti-rejection medicines. Eligibility is decided by a transplant centre after assessment, never by a website.
TSATTests and numbers: A blood test showing how much iron is actually available for making red blood cells, as opposed to how much is sitting in storage. It is read together with ferritin.

UltrafiltrationTreatments: Removing excess fluid during dialysis. The UF rate is how fast it comes off, and taking it off too fast is what causes the crashes, the cramps and the washed-out feeling afterwards. The lower your weight gain between sessions, the gentler the rate can be.
Ultrafiltration failureComplications: When the peritoneal membrane stops being able to remove enough fluid, usually after years of peritoneal dialysis. It is the main reason people move from peritoneal dialysis to haemodialysis, and it is a normal part of the treatment running its course.
UraemiaComplications: The build-up of waste products in the blood when the kidneys fail. It causes nausea, itching, tiredness, poor appetite, poor concentration, restless legs, poor sleep and a metallic taste. It is these symptoms, rather than a number on a blood test, that usually decide when dialysis should start.
Uraemic pruritusComplications: The persistent itching that affects a large minority of people on dialysis. It wrecks sleep and mood, it is strongly under-treated, and there are treatments for it, including newer ones. It is not something you simply have to live with. Tell your team.
URRTests and numbers: A simpler measure of dialysis adequacy: the percentage by which the urea in your blood fell during a session. It is not interchangeable with Kt/V, because it ignores the fluid taken off and the length of the treatment.

VintageTests and numbers: How long someone has been on dialysis. It matters clinically, because a long time on dialysis brings its own complications, such as joint problems from amyloid deposits.
VirologyTravel: Your hepatitis B, hepatitis C and HIV status. Dialysis units must know it, because they keep patients who are positive separate from those who are not. It is the first thing any unit will ask for if you want to dialyse away from home, and it is why virology bloods are usually done about six to eight weeks before you travel.
Vitamin D analogueMedicines: Not the same as the vitamin D you buy in a shop. Failing kidneys cannot perform the final step that activates ordinary vitamin D, so these medicines come ready-activated. They are used to calm an overactive parathyroid gland, not simply to top up a vitamin, and they need care because they raise calcium and phosphate absorption.

A word we have not explained?

If your team used a word that is not here, tell us and we will add it. Write to [email protected]. And if a word here matters for a decision you are facing, take it back to your kidney team. Understanding the word is the start of the conversation, not the end of it.

Looking for something more specific? The questions people actually ask covers the ones that are harder to put into words, and kidney care in Seychelles covers what is local.

Sources

Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease (KDIGO, 2024)
Clinical Practice Guideline for Vascular Access: 2019 Update (KDOQI, American Journal of Kidney Diseases, 2019)
Clinical Practice Guideline for Nutrition in CKD: 2020 Update (KDOQI, American Journal of Kidney Diseases, 2020)
ISPD Peritonitis Guideline Recommendations: 2022 Update on Prevention and Treatment (International Society for Peritoneal Dialysis, 2022)
Kidney Failure: Hemodialysis, Peritoneal Dialysis, Kidney Transplant, Conservative Management (National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK))
Hemodialysis Access, and Phosphorus and Your Diet (National Kidney Foundation)

What all the words mean

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A word we have not explained?

Sources